/* Optimized version of the standard memchr() function.
This file is part of the GNU C Library.
- Copyright (C) 2000 Free Software Foundation, Inc.
+ Copyright (C) 2000-2017 Free Software Foundation, Inc.
Contributed by Dan Pop <Dan.Pop@cern.ch>.
The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
/* Return: the address of the first occurence of chr in str or NULL
Inputs:
- in0: str
- in1: chr
- in2: byte count
+ in0: str
+ in1: chr
+ in2: byte count
This implementation assumes little endian mode. For big endian mode,
the instruction czx1.r should be replaced by czx1.l.
possible; the remaining few bytes are searched one at a time.
The word by word search is performed by xor-ing the word with a word
- containing chr in every byte. If there is a hit, the result will
- contain a zero byte in the corresponding position. The presence and
+ containing chr in every byte. If there is a hit, the result will
+ contain a zero byte in the corresponding position. The presence and
position of that zero byte is detected with a czx instruction.
All the loops in this function could have had the internal branch removed
#include <sysdep.h>
#undef ret
-#define saved_pfs r14
#define saved_pr r15
#define saved_lc r16
#define chr r17
#define len r18
-#define pos0 r20
+#define last r20
#define val r21
#define tmp r24
#define chrx8 r25
#define str in0
-ENTRY(memchr)
- alloc saved_pfs = ar.pfs, 3, 0, 29, 32
+ENTRY(__memchr)
+ .prologue
+ alloc r2 = ar.pfs, 3, 0, 29, 32
#include "softpipe.h"
.rotr value[MEMLAT+1], addr[MEMLAT+3], aux[2], poschr[2]
.rotp p[MEMLAT+3]
- mov saved_lc = ar.lc // save the loop counter
+ .save ar.lc, saved_lc
+ mov saved_lc = ar.lc // save the loop counter
+ .save pr, saved_pr
mov saved_pr = pr // save the predicates
- mov ret0 = str
- and tmp = 7, str // tmp = str % 8
+ .body
+ mov ret0 = str
+ add last = str, in2 // last byte
+ and tmp = 7, str // tmp = str % 8
cmp.ne p7, p0 = r0, r0 // clear p7
extr.u chr = in1, 0, 8 // chr = (unsigned char) in1
mov len = in2
.str_aligned:
cmp.ne p6, p0 = r0, r0 // clear p6
shr.u loopcnt = len, 3 // loopcnt = len / 8
- and len = 7, len ;; // remaining len = len & 7
+ and len = 7, len ;; // remaining len = len & 7
adds loopcnt = -1, loopcnt
mov ar.ec = MEMLAT + 3
mux1 chrx8 = chr, @brcst ;; // get a word full of chr
mov ar.lc = loopcnt
mov pr.rot = 1 << 16 ;;
-.l2:
+.l2:
(p[0]) mov addr[0] = ret0
-(p[0]) ld8 value[0] = [ret0], 8
+(p[0]) ld8.s value[0] = [ret0], 8 // speculative load
+(p[MEMLAT]) chk.s value[MEMLAT], .recovery // check and recovery
(p[MEMLAT]) xor aux[0] = value[MEMLAT], chrx8
(p[MEMLAT+1]) czx1.r poschr[0] = aux[1]
(p[MEMLAT+2]) cmp.ne p7, p0 = 8, poschr[1]
(p7) br.cond.dpnt .foundit
br.ctop.dptk .l2
.srchfew:
- adds loopcnt = -1, len
+ adds loopcnt = -1, len
cmp.eq p6, p0 = len, r0
(p6) br.cond.spnt .notfound ;;
mov ar.lc = loopcnt
;;
cmp.eq p6, p0 = val, chr
(p6) br.cond.dpnt .foundit
- br.cloop.sptk .l3 ;;
+ br.cloop.sptk .l3 ;;
.notfound:
cmp.ne p6, p0 = r0, r0 // clear p6 (p7 was already 0 when we got here)
mov ret0 = r0 ;; // return NULL
.foundit:
-(p6) adds ret0 = -1, ret0 // if we got here from l1 or l3
+ .pred.rel "mutex" p6, p7
+(p6) adds ret0 = -1, ret0 // if we got here from l1 or l3
(p7) add ret0 = addr[MEMLAT+2], poschr[1] // if we got here from l2
mov pr = saved_pr, -1
- mov ar.pfs = saved_pfs
mov ar.lc = saved_lc
br.ret.sptk.many b0
-END(memchr)
+.recovery:
+#if MEMLAT != 6
+# error "MEMLAT must be 6!"
+#endif
+(p[MEMLAT-6]) add ret0 = -8, ret0;;
+(p[MEMLAT-5]) add ret0 = -8, ret0;;
+(p[MEMLAT-4]) add ret0 = -8, ret0;;
+(p[MEMLAT-3]) add ret0 = -8, ret0;;
+(p[MEMLAT-2]) add ret0 = -8, ret0;;
+(p[MEMLAT-1]) add ret0 = -8, ret0;;
+(p[MEMLAT]) add ret0 = -8, ret0;;
+(p[MEMLAT+1]) add ret0 = -8, ret0;;
+(p[MEMLAT+2]) add ret0 = -8, ret0;;
+.l4:
+ mov addr[MEMLAT+2] = ret0
+ ld8 tmp = [ret0];; // load the first unchecked 8byte
+ xor aux[1] = tmp, chrx8;;
+ czx1.r poschr[1] = aux[1];;
+ cmp.ne p7, p0 = 8, poschr[1];;
+(p7) add ret0 = addr[MEMLAT+2], poschr[1];;
+(p7) cmp.geu p6, p7 = ret0, last // don't go over the last byte
+(p6) br.cond.spnt .notfound;;
+(p7) br.cond.spnt .foundit;;
+ adds ret0 = 8, ret0 // load the next unchecked 8byte
+ br.sptk .l4;;
+
+END(__memchr)
+
+weak_alias (__memchr, memchr)
+libc_hidden_builtin_def (memchr)
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